> why use HTMX when it really seems like (a heavier) Datastar-lite?

The reason to use htmx is that it has a simpler interface optimized for the majority use-case.

With htmx, you are largely tied to a request/reply paradigm. Something happens that triggers a request (e.g. user clicks a button, or some element scrolls into view), htmx sends the request, and then it processes the response. The htmx interface (`hx-get`, hx-trigger`) is optimized to make this paradigm extremely simple and concise to specify.

Datastar's focus (last I checked) is on decoupling these two things. Events may stream to the client at any time, regardless of whether or not they were triggered by a specific action on the client, and they get processed by Datastar and have some effect on the page. htmx has affordances for listening to events (SEE extension, new fetch support) and for placing items arbitrarily on the page (out-of-band swaps) but if your use-case is a video game or a dashboard or something else where the updates are frequently uncorrelated with user actions, Datastar makes a lot of sense. It's a bit like driving a manual transmission.

Delaney is fond of saying that there's no need for htmx when Datastar can technically do everything htmx can [0]. But I think this misses the point of what makes htmx so popular: most people's applications do fit within a largely request/reply paradigm, and using a library that assumes this paradigm is both simpler to implement and simpler to debug. As an htmx maintainer, I often encourage people to even use htmx less than they want to, because the request/reply paradigm is very powerful and the more you can adhere to browser's understanding of it, the more durable and maintainable your website will be [1].

[0] https://data-star.dev/essays/v1_and_beyond

[1] https://unplannedobsolescence.com/blog/less-htmx-is-more/

Respectfully, almost everything you said is just plain wrong.

1. Datastar supports req/reply just fine - be it via normal text/html responses, or SSE (0, 1, or infinity responses) https://data-star.dev/reference/actions#response-handling. So, the crux of your argument is moot...

Moreover, if htmx's real value is ajax request/response, then why are you introducing SSE as a first-class citizen now?

2. Datastar has data-on, and various other attributes, that allow for triggering far more actions than just backend requests, from far more (any) events. I'm glad to see that htmx is now following suit with hx-on, even if it is apparently limited in capabilities.

3. Datastar can do OOB-swaps just fine - that's literally the core functionality, via (their own, faster) idiomorph.

4. Its a misnomer that Datastar is for video games etc - again, as described above, it can do all of the simple things that that HTMX can do, and more. And, again, why is HTMX introducing SSE if its so apparently unnecessary and unwieldy?

5. What makes htmx popular is that it was the first library to make declarative fragment swapping easy. And Carson is just a god-tier marketer. Its nice to see that he's now realized that Delaney was on to something when he wanted to introduce all of these v4 features to HTMX 3 years ago, but was (fortunately for us happy users) forced to go make Datastar instead.

6. We havent even talked about one of the key features - declarative signals. Signals are justifiably taking over all of the JS frameworks and there's even an active proposal to make them part of the web platform. D* makes them simpler to use than any of them, and in a tiny package.

I, Delaney, and all other D* users are grateful for HTMX opening this door. But I reiterate my original question - now that HTMX is becoming Datastar-lite, why not just use Datastar given that the powerful extras don't add any complexity and comes in a smaller package?

Why bother with v4 at all? If it dilutes that simpler interface?

I think that even with req/resp morph leads to a simpler majority use case and that's what Turbo and Datastar have both shown. No?